A Minimally Disruptive D-C Micro Grid for Hybrid Consumer Applications

DC Micro-grids have traditionally had end use loads that are either rated to operate on the nominal rated AC supply, fed by inverters downstream of the energy storage device, or low voltage DC loads which are specifically designed for the appropriate DC voltage level. This increases the overall cost of the system. The recent trend in consumer appliances is to have a front end converter at the input, and this enables operation on both AC and DC, thereby enabling the use of a DC supply to directly power such appliances. This paper proposes a DC microgrid that is compatible with existing consumer appliances thereby increasing the acceptability of such a system. The reliability of the proposed system is also higher than existing low voltage DC micro-grid systems with inverters to condition the supply for commercially available consumer appliances. A variety of commercially available household appliances is tested on the proposed DC Micro-grid, and the results confirm satisfactory operation. Low cost modifications are also suggested for certain classes of loads to make them compatible with the proposed DC micro-grid.